That’s part of the SCSS from my Stately package for Umbraco - it’s positioning the Stately icons with respect the current nesting level of the main content tree.

There’s a few things going on here that might be interesting.

The depth mixin is generating a chained selector to target nodes at any menu level between 1 and 10, while the fromLeft mixin is calculating the left positioning of the Stately icon, again with respect to the menu depth.

I said earlier, I was writing this styling bound by the constraints that exist in the Umbraco back end - I had to find a way of calculating the menu depth without resorting to adding extra markup to the content tree. Using a loop to generate the CSS means that while the output isn’t the most elegant, it’s simple to manage and update if/when required.